The ABC's are for Aquanaut, Buoy, and Continental Shelf, or if you prefer lower case letters, for aquaculture, bore, and current. This is an illustrated dictionary of oceanography (with two entries for each letter) having the same format as Asimov's ABC's of Space (1969). Limitations are imposed by this format: there is little coherence in moving from topic to topic and some topics are included only because of the paucity of relevant words starting with particular letters. Such is the case with entries like quadrature, xiphius, or yowling. One also wonders why this particular lexicon was chosen -- why, for example, we have buoy and bore rather than bathysphere and breakwater. The book is more advanced in level and scope than Goldin's The Bottom of the Sea (1966); in these respects it is closer to The First Book of the Ocean (1961) by the Epsteins, which generally presents more explanatory material while Asimov's information is more up to date. A peripheral book of definitions and descriptions, attractively put together and well illustrated.